Here's a moderately priced coloring book that comes with an entertaining (as well as educational) twist! 

Illustrator Llyn Hunter has dramatically rendered - in alphabetical order - 28 prehistoric beasts as they might have appeared in their natural habitats millions of years ago. extensive notes contain fascinating background information on the mighty Apatosaurus, the herbivorous Brachiosaurus, the "helmeted" Corythosaurus and other Mesozoci monsters. 

Young amateur paleontologists are provided with a list of sources for further reading, plus helpful suggestions for coloring the drawings.